Storage: Keep battery on solar charge or?

[TheRedDawn]

Regarding proper battery maintenance, should we keep our solar plugged in while our Casita is not in use?

We have an Optima Blue Top deep cycle battery.

Thanks!

[Mikmay]

Originally Posted by TheRedDawn

Regarding proper battery maintenance, should we keep our solar plugged in while our Casita is not in use?

We have an Optima Blue Top deep cycle battery.

Thanks!

Yes if you have a charge controller as it will always keep the battery charged with out over charging even if you keep it garaged .

[Raz]

The optima is an AGM battery. Unlike wet cells AGM batteries are very slow to self discharge. Mine sits in my basement for 6 months. I charge it once. When not in use I disconnect it from the trailer to avoid parasitic discharge. If you elect to keep a charger on it make sure its set for 3 stage charging.

[sokhapkin]

To my experience, it is better to not trust auto chargers while the battery is in a storage mode, but allow charging for 1-2 days and then disconnect it from charger for a month. There is no science behind that, but just my experience.

[Backwater Bill]

Originally Posted by sokhapkin

To my experience, it is better to not trust auto chargers while the battery is in a storage mode, but allow charging for 1-2 days and then disconnect it from charger for a month. There is no science behind that, but just my experience.

My experience too. If there is a power outage, especially a quick one my charger gets a false reading of the battery and goes into heavy duty bulk charging mode. Not so concerned about my solar controller.

[Byron Kinnaman]

This all depends on the charge controller. Most designed for continuous connection as is typical for roof mounted panel(s). Read the manual for the charge controller and see what it says. If you don't have the manual find manufacturer and model number the chances pretty darn good you can down load the manual from the manufacturer's web site.

[Raz]

Originally Posted by sokhapkin

To my experience, it is better to not trust auto chargers while the battery is in a storage mode, but allow charging for 1-2 days and then disconnect it from charger for a month. There is no science behind that, but just my experience.

Yea, that too..

[Laps]

I kept a Optima Red Top battery on a charger for 12 years, hooked up to a car, and it lasted that long and only slowly went dead.

[Raspy]

Originally Posted by Backwater Bill

My experience too. If there is a power outage, especially a quick one my charger gets a false reading of the battery and goes into heavy duty bulk charging mode. Not so concerned about my solar controller.

This won't hurt a thing. The charger will immediately detect that the battery is already fully charged and return to the maintenance charge. That's it's job and what it is designed to do. Also a bulk charge that gets to 14.1 volts is exactly what your car is doing every time you drive. A running car has a battery voltage of 14.1 to 14.4 continually. Batteries are fine with that, but it's too high for continuous storage. Not because it will hurt the battery, but because it will use water if it has vented caps and it will run warmer than necessary. Undercharging is what kills them.

[Raspy]

Originally Posted by sokhapkin

To my experience, it is better to not trust auto chargers while the battery is in a storage mode, but allow charging for 1-2 days and then disconnect it from charger for a month. There is no science behind that, but just my experience.

Definitely don't trust a ferro-resonant charger because they will kill your battery, but a modern multi-stage battery tender is fine and even desired for continuous use during storage.

[Backwater Bill]

Originally Posted by Raspy

This won't hurt a thing. The charger will immediately detect that the battery is already fully charged and return to the maintenance charge. That's it's job and what it is designed to do. Also a bulk charge that gets to 14.1 volts is exactly what your car is doing every time you drive. A running car has a battery voltage of 14.1 to 14.4 continually. Batteries are fine with that, but it's too high for continuous storage. Not because it will hurt the battery, but because it will use water if it has vented caps and it will run warmer than necessary. Undercharging is what kills them.

Unfortunately it does not immediately detect the state of charge and drop into float mode but reads a 60% charge and goes from there. If I unplug the charger and plug it back in within about 30 seconds it will do the same thing. But it makes sense that it shouldn't do any harm. When I stored my batteries on the charger I tended to only charge them about once a month for a couple of days and give them a good shake to stir up the electrolyte at the same time. Going to leave them on solar this winter and shake them up by travelling a bit more.

[Raz]

Every year we have the discussion of how folks leave their battery on a charger all winter. And every year at least one destroys his battery because he neglected to periodically check it and the electrolyte boiled away. As the op has an AGM battery, that's not a concern.

[Roger Kimble]

Our trailer is out side all the time, We leave the solar on it all the time, I replace the battery every 3 or 4 years, not because I have to, just to be on the safe side, winter camping.

[Wayne Collins]

Originally Posted by TheRedDawn

Regarding proper battery maintenance, should we keep our solar plugged in while our Casita is not in use?

We have an Optima Blue Top deep cycle battery.

Thanks!

A lead/acid battery can be left off the charger of many months as long as it is fully charged and disconnected, and the top is clean of dirt and moisture.